From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A7F2C433E0 for ; Tue, 9 Jun 2020 15:37:02 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F094A20774 for ; Tue, 9 Jun 2020 15:37:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="J6dXtido" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F094A20774 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=aNSNyaYZegQYk5Ea0ECZ9r3uCThlTwcJNE0abQiwrqQ=; b=J6dXtidoUEtN3K DTkKM50bNaz2PlVX5NrR05KkytNEE4zz+nPFR3oIQGJNEFpHLAPUp8M2wE8DBCWtXbZO+lB9D8nKn 12GtnfyPcnLk9SNPfGtQDsTOrVDRNM7P8yCMm0P2IbzRntqimyX+5wdvlE7v1QGbiOpz2VPGwnWf/ 7M9PNJb1sujsHUNuevK1sdB2yRTwOJPFC1q3y6lQijv4PbndvZogW5T42N5VJPrDzJ9dc26A9QQgH QjX8pnYsVjjpjB+852DwdECoNVW9cr0QbBJso1sa+FOMYgei6YDkdL3JhXmYYiDpozjSodp7nV3x9 YrRWJPSxjdRA0pLQ+z/A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jigJ6-0000lP-30; Tue, 09 Jun 2020 15:36:56 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jigJ2-0000kq-3m for linux-arm-kernel@lists.infradead.org; Tue, 09 Jun 2020 15:36:53 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id B476668B02; Tue, 9 Jun 2020 17:36:46 +0200 (CEST) Date: Tue, 9 Jun 2020 17:36:46 +0200 From: Christoph Hellwig To: dillon min Subject: Re: [PATCH 2/2] arm-nommu: Add use_reserved_mem() to check if device support reserved memory Message-ID: <20200609153646.GA17969@lst.de> References: <1591605038-8682-1-git-send-email-dillon.minfei@gmail.com> <1591605038-8682-3-git-send-email-dillon.minfei@gmail.com> <90df5646-e0c4-fcac-d934-4cc922230dd2@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200609_083652_328734_E2BFBB98 X-CRM114-Status: GOOD ( 12.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kate Stewart , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Vladimir Murzin , Alexandre Torgue , Linux Kernel Mailing List , linux@armlinux.org.uk, linux-stm32@st-md-mailman.stormreply.com, Rob Herring , Linux ARM , Maxime Coquelin , tglx@linutronix.de, info@metux.net, hch@lst.de, allison@lohutok.net Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jun 09, 2020 at 11:22:24PM +0800, dillon min wrote: > Hi Vladimir, > > Thanks for reviewing. > > Hi Christoph Hellwig, > > I just want to know if kernel dma mapping/direct is focused on > platforms with MMU. > leave arch code to handle dma coherent memory management themself for > no-MMU platform. No, I'd really like to consolidate everything that isn't overly arch specific eventually. > > so, you just return error code in kernel/dma/mapping.c,direct.c > without CONFIG_MMU defined ? > which means dma-direct mapping doesn't support !CONFIG_MMU is not a > bug, but design as it's. > or, just return error code currently, will add dma direct mapping > support for !CONFIG_MMU in the > future? > > As Vladimir Murzin's suggestion has changes in kernel code, I need > your input to get > the design goal about dma-direct mapping, thanks. Can someone repost the whole patch? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel